Time controlled radio frequency preselection apparatus



April 13, 1954 w. D. GIBBS v 7 TIME CONTROLLED RADIO FREQUENCYPRESELECTION APPARATUS Filed March 9, 1949 Y Y 2 Sheets-Sheet 1/w'illiam Gibbs 2 Sheets-Sheet 2 April 13, 1954 w. D. GIBBS TIMECONTROLLED RADIO FREQUENCY PRESELECTION APPARATUS Filed March 9, 1949 4m A F ATTORNEY Patented Apr. 13, 1954 UNITED STATES PATENT OFFICE TIMECONTROLLED RADIO FREQUENCY PRESELEUTION APPARATUS William D. Gibbs,Pasadena, Calif., assignor to Phantom Dial Company, Pasadena, Calif., a

partnership 1 Claim. 1

This invention relates generally to the class of radiant energy and isdirected particularly to improvements in apparatus for connection'withreceivers of radio frequency impulses, by means of which pro-selectionof frequencies of different wave lengths may be made to be fed into thereceiver at predetermined time intervals.

A particular object of the present invention is to provide an apparatusadapted to be connected with any standard type of radio broadcastreceiver, by means of which at predetermined time intervals, preselectedbroadcasting stations, for which circuit of the apparatus arepace-tuned, will be automatically connected with the broadcast receivercircuit whereby the program of the pro-selected broadcasting stationwill be heard through the broadcast receiver system.

Another object of the invention is to provide an apparatus for theselection at predetermined time intervals, of radio frequencies orstations or electric circuits of any type whatsoever, used inconjunction with any radio signal receiving device whereby the radiosignal receiving device may be set to receive one pre-selected frequencywhich will be a beat frequency produced by the time controlled stationselecting device by mixing a signal frequency received by one of severalpro-tuned circuits with a locally generated signal.

Another object of the invention is to provide an improved clockcontrolled circuit closer by means of which pro-selected circuits may beclosed at pro-selected time intervals.

Still another object of the invention is to pro-- vide an improved clockcontrolled circuit closer having novel means for selecting ordesignating the dilferent times at which the circuit selecting mechanismwill be caused to function, said means comprising a plurality of currentconducting pins which are placed at desired locations around the face ofa clock dial at points indicating pro-selected times and a currentconducting clock hand which contacts said pins at the predetermined timeperiod for closing a circuit by means of which a pro-tuned receivingcircuit i selected and closed.

Other objects and advantages of the invention will become apparent asthe description f the same proceeds and the invention will be bestunderstood from a consideration of the following detailed descriptiontaken in connection with the accompanying drawings forming a part of thespecification, with the understanding, however, that the invention isnot to be limited to the exact details of construction shown anddescribed 2 since obvious modifications will occur to a person skilledin the art.

In the drawings:

Figure 1 is a view in front elevation of a unit constructed inaccordance with the present invention, showing the time setting dial andstation selectors.

Figure 2 is a view in top plan of the same, showing certain of theelectrical units in plan,

Figure 3 is a view in side elevation of the step relay and duplex switchunit controlled thereby.

Figure 4 is a detail section, on an enlarged scale, taken substantiallyon the line =i4 of Figure 2.

Figure 5 shows the circuit diagram of the invention.

Referring now more particularly to the drawing reference will first bemade to the mechanical features of the invention by means of which theselection of the dilferent time periods is made, at which periods acircuit selector switch will be operated to bring in pro-selectedprograms.

The present invention may be incorporated in the structure of a cabinetof an broadcast or television receiver or it may be set up as a separateunit adapted to be connected to a standard broadcast or televisionreceiver, as may be desired. It is here illustrated, and will bedescribed, as a separate unit for connection with a standard type ofbroadcast television or other receiver and accordingly the illustrationas presented in Figures I to 4 discloses a mounting panel Ill connectedin the usual manner to a base ll upon which different units used in thecircuit are assembled and upon the underside of which are locatedvarious switches, condensers and the major portion of the wiring in thecustomary manner.

Mounted in the panel Ii is the circular metal plate 52 which constitutesa clock dial, around which the hours are noted as shown, either upon thepanel or upon the plate. This plate l2 carrie a circular series ofopenings or sockets 13 in which are adapted to be inserted metal pins54. These sockets are located one at each of the hour marks with threebetween so that from any one hour mark or notation a pin It may be placeto designate any of the fifteen minute intervah between the hours.Accordingly as shown, in addition to the socket i 3 at each of the hourmarks there are three sockets between each two hour marks.

Mounted upon the back of the panel H) is an electric clock motor unit ofthe type commonly employed in electric clocks, the same beingconventionally illustrated and generally designated [5. Since such clockunits are of well known form and since the clock per se does not form apart of the present invention no detailed illustration or description ofthe same is considered necessary.

The hours hand shaft 28 for the clock unit 15, i carried through thecenter of the metal dial l2 and has secured to it the two joinedoppositely directed hands 15, each of which carries at its point or tipthe thin flexible contact fingers ll which is of proper length andflexibility to wipe across a pin it whereby to make electrical contactwith the pin without interfering with the turning of the hand by theclock mechanism.

The clock mechanism :5 is secured to the back of the dial 12 upon aninsulation block it and the shaft 29 upon which the hands it are mountedand which, as above stated comprises the hour hand shaft of the clockworks, extends through an insulation sleeve l9 by which it is kept fromelectrical contact with the metal plate [2.

Referring now to the circuit diagram the reference character 2!designates the antenna ground circuit in which is included the tuningcondenser 22 and the primary winding "23 of the antenna coupler which isgenerally designated 24, the secondary winding of which is designated25.

The numeral 23 designates a vacuum tube of the mixer-oscillator type, inthe grid circuit 2'? of which is connected a selected one of thepretuned receiver circuits, by means of the hereinafter describedswitches.

Any desired number of tuning circuits may be employed. Four of suchcircuits are here shown connected in parallel and designated 28, 29, 3tand 3!. Each of these circuits is pre-set or tuned to a selectedfrequency by means of the tuning condensers 32, 33, 34 and 35. Suchfrequencies may represent the broadcasting frequencies of broadcastingstations which the operator of the device desires to have automaticallytuned in at the selected time periods. While only four tuning circuitshave been shown it will be obvious that any number may be set up in thegroup as desired.

The numerals 36, 37, 38 and 39 designate switches having the fixedterminals a, b, c, d and e. Each of the tuned circuits is electricallyconnected with the corresponding fixed terminal of each of theseswitches. That is, as shown, the circuit 28 is connected with the fixedterminal a of each switch; circuit 29 is connected with the fixedterminal 2) of each switch, and so on.

The switches 36 to 39 inclusive are each provided with the usual movableswitch blade ,1 and such switch blades are each connected with acorresponding switch blade f of a second group of switches which aredesignated 36a, 31a, 38a and 39a by shafts so, ll, 32 and 43,respectively, which shafts carry the control knobs 40a, Ala, 42a andetc, located at the front of the panel It as shown in Figure l.

The switches 35a to 3% control oscillator circuits 28a, 28b, 28c and28d. Each of these oscillator circuits includes a tuning condenser, suchcondensers being designated 32a, 32b, 32c and 32d.

The switches 36a to Sta, like the switches 36 to 39 have the fixedpoints 0. b 0 d and e and each oscillator circuit 28a to 2% inclusive isconnected with a fixed terminal of one of the associated switches, thatis, each circuit is connected to a corresponding terminal of each of theswitches.

The numeral fi l designates an intermediate frequency transformer. theprimary winding 45 of which is connected in each of the oscillatorcircuits while the terminals of the secondary winding 45 are connectedwith the antenna and ground posts of the radio receiver in associationwith which the present apparatus is used.

Trimmer condensers 45a and 4611 are connected across the windings in thecustomary manner as shown.

The oscillator circuits 28a to 28d inclusive are connected, as shown, toone winding 41 of a coupler 48, the other or primary winding 49 of whichis connected in the cathode circuit of the mixer tube.

The numerals 5t and 5t designate a pair of coupled switches which areactuated by a step relay, generally designated R which is energized atselected intervals by the clock operated mechanism. These switches areaccordingly changed simultaneously and periodically by the clockmechanism and with each change a tuning circuit and its associatedoscillator circuit, is either closed or maintained closed, accordinglyto the pro-setting of the knobs 4ta43a.

As shown each of the switches 56 and 5! has a fixed terminal for each ofthe switches 3b to 39 respectively and the switches Sta to Starespectively.

Switch 50 has each of its terminals Etc, 50b, 59c and 56d connected asshown respectively with the movable switch blades f of switches 33 to39.

Switch 5! has each of its fixed terminals 5|a, 55b, 5k: and Sidelectrically connected with the movable switch blade I of the oscillatorcircuit switches 35a to 3912 respectively as shown.

The movable switch blades Fate and file are electrically connected bythe connector 52 and the movable blades of these two switches 50 and 5|are connected with the step relay R to be turned simultaneously when therelay is energized.

As shown in Figure 3 the step relay includes a shaft 53 which isdirectly operatively coupled with the switch blades Elie and tie andextends through the panel ill to the front of the latter where itcarries a knob 54. The face of the panel is provided with designationsidentifying each of the station selector switch buttons ltal3a as shownand since the indicator knob 54 will be given partial rotation with eachenergization of the step relay it can be seen at a glance which of thepre-set or pro-tuned circuits 293i is functioning at the moment. Also bymeans of the knob E l resetting of the switches 5il5i to startingposition can be easily effected.

As shown in the diagram the step relay circuit may be completelyseparate from the other circuits, with a separate source of electricalenergy for its operation. In this arrangement, the metallic dial wouldbe grounded as indicated at 55 while the clock hand shaft 2t would beconnected by a conductor 56 with one side of a suitable source ofelectric potential 57, the other side of such potential being groundedthrough the relay coil 58 as shown.

In the use of the present device each of the circuits 28 to 3! will betuned to a selected broadcasting station frequency where it will staytuned at all times during use of the device, and the associatedoscillation circuit will be tuned to such a different frequency that thediiierence between the two frequencies, when the same are mixed in themixer-oscillator tube 28, will produce a beat frequency which thebroadcast receiver is pretuned and stays tuned, to receive. As anexample if the circuit 28 is tuned to respond to a broadcast frequencyof 980 kilocycles the corresponding oscillation circuit 28a might betuned to generate a frequency of 1200 kilocycles. When the incomingfrequency signal of 980 kilocycles is mixed with the generated frequencyof 1200 kilocycles the output from the intermediate frequencytransformer would be the difference between the two or 220 kilocycles.

The next pre-tuned circuit 29 might be set to respond to frequencyimpulses of 1500 kilocycles. In this case the corresponding circuit 29awould be tuned to generate a signal frequency of 1720 kilocycles andwhen these frequencies are mixed in the mixer-oscillator tube the beatfrequency resulting and fed to the broadcast receiver would also be 220kilocycles. The other pre-tuned receiving circuits and their associatedtuned frequency generating circuits would be correspondingly related sothat the same beat frequency would always be introduced to the broadcastreceiver and consequently the broadcast receiver would be tuned or setat their beat frequency or at any other selected beat frequency producedby the selector apparatus.

The sequence of stations or frequencies received is established by thesetting of the switch buttons a to 43a. The turning of these buttonswill set the connected pairs of switches 36-36(1, 3'l31a etc., as willbe readily apparent. If for example, circuit 28 is pre-tuned tobroadcast station WRC having a broadcast frequency of 980 kilocycles andcircuit 29 is pre-tuned to broadcast station WTOP having a broadcastfrequency of 1500 kilocycles and it is the desire of the user of thedevice to receive the program of WRC from 1:00 oclock until 2:00 oclockand WTOP from 2 :00 oclock until 3:00 oclock, a contact pin I4 would beplaced in the socket [3 at the 1:00 oclock position on the dial and asecond pin would be placed in a socket at the 2:00 oclock position onthe dial.

Station selector button 40a would then be set to designate station WRCwhich would Place the switch blades 1 and f of switches 36 and 36a onthe terminals aa and station selector button Ala would be turned todesignate station WTOP which would place the switch blades 1 and f ofswitches 31-31a on the terminals 12-12 of those switches.

The reset knob 54 of the clock operated switches 5l would be previouslyset at the start position. With these settings it will be seen that withthe clock properly set and operating, at 1:00 oclock the contact I! ofthe clock hand would engage the pin in the 1:00 oclock socket toenergize the step relay. When so energized the switch blades 50c and Hewould be brought into contact with the terminals 50a--5la, thus closingor energizing the tuned circuits 28- 28a to receive the broadcaststation which circuit 28 is tuned to. After the lapse of one hour whenthe stations are to be changed, the clock hand terminal or contact I!will engage the metalic pin in the socket at the 2:00 oclock positionwherein the step relay will be again energized and the switches 505|will be turned to move the switch blades to the second position intocontact with terminals 50b-5lb. This will bring into action the switches3131a together with the tuned circuits 2929a and so on.

From the foregoing it will be readily apparent that with the apparatusherein disclosed various combinations of any number of broadcaststations may be set up to be automatically tuned in any pre-selectedtime periods and that after the tuning circuits have once been set tothe desired station broadcast frequencies no further settings or changeswill have to be made and the selection of the time periods for anynumber of programs from the different stations can be easily and quicklymade merely by the process of settin the station selector knobs lla43aand then placing the contact pins in the desired time positions aroundthe time or clock dial.

I claim:

Apparatus for automatically receiving pre-selected broadcast electricalfrequencies at pre-selected time periods, comprising a plurality ofreceiving circuits each pre-tuned to a different selected frequency, asignal receiving system coupled with said circuits, a plurality ofoscillator circuits, each oscillator circuit being tuned. to have afrequency difference from one particular receiving circuit to give whenmixed therewith a predetermined beat frequency which is the same for anyother oscillation circuit and its associated receiving circuit, meansfor selecting a pre-tuned receiving circuit and an associated oscillatorcircuit simultaneously, said means comprising a group of multi-pointswitches of the same numher as that of the receiving circuits each ofwhich is connected to one point of each switch, a second group ofmulti-point switches of the same number as that of the oscillatorcircuits each of which is connected to one point of each of the latterswitches, a movable point contacting blade for each of said switches, ashaft having the blades of the switches of each of the associated tuningand oscillator circuits mounted thereon, a knob on one end of each ofsaid shafts for turning the same to pre-select the frequencies to bereceived, a pair of multi-point control switches, one having each of itspoints connected with each of the blades of the tuning circuit selectorswitches and the other each 01 its points connected with the blades ofthe oscillator circuit selector switches, a movable point contactingblade cooperative with the points of each of said control switches,another shaft carrying the latter blades, and a time controlled relayfor imparting a step-by-step rotary motion to the latter shaft, amixer-oscillator having the receiving and oscillator circuits connectedtherewith for producing said beat frequency, means for feeding the beatfrequency to a receiver tuned to the beat frequency, and means forelectrically coupling a preselected tuning circuit with its particularoscillator circuit at a pre-selected time period.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,977,330 Weckler Oct. 16, 1934 2,029,909 Cassell Feb. 4, 19362,068,227 Cutler et a1 Jan. 19, 1937 2,122,779 Peters July 5, 19382,201,162 Elliott May 21, 1940 2,326,930 Crowder Aug. 17, 1943 2,332,767Wagner Oct. 26, 1943 2,337,568 Owens Dec. 28, 1943 2,342,814 Miller Feb.29, 1944 2,501,274 Hamilton Mar. 21, 1950

